Imperial Oil finds source, but not cause of Mackenzie River leak

Imperial Oil has now identified the section of pipeline at its Norman Wells facility from which 55,000 litres of treated water escaped last month.

The location of the leak, a section of exposed pipeline on the bed of the Mackenzie River, appears to confirm that produced water – a form of industrial waste created during oil extraction – entered the river.

Imperial had previously said it was investigating whether produced water reached the river. On Thursday, spokesperson Lisa Schmidt confirmed by email that the leak had occurred “in the section of the produced water line that is under the Mackenzie River.”

Schmidt said the cause was still being determined.

In a filing with NWT regulators last week, an environmental worker at Imperial said the leak occurred in an 18-metre section of exposed pipeline between Bear Island and Goose Island in the Mackenzie River.

“Based upon our findings and as a precaution, we have also shut down other lines in the vicinity of this line and are assessing potential plans for repairs and remediation work,” said Schmidt. The Norman Wells facility as a whole remains operational.

While residents downstream have complained to the CBC of a sheen on the water, Imperial said water samples taken between August 10 and August 12 showed “no indications there is a risk to public health or freshwater aquatic life downstream.”

“The primary contaminants of potential concern associated with produced water are chlorides and hydrocarbons. Chloride levels were below guidelines and consistent across all samples, including the location upstream of the release,” Schmidt stated. “All hydrocarbon concentrations were below laboratory detection limits across all sampling locations.”

She added: “We apologize for any disruption or inconvenience that this incident has caused the community. Our primary concern remains maintaining the safety of our employees, our contractors and our neighbours.”